1. Field of the Invention
The present invention relates to a slider link press. More precisely, the present invention relates to a slider link press having high operational precision and increased pressing force.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 11-226788, presently owned by Applicant, is an example of a slider link press. The slider link press includes a crank shaft that rotates in a horizontal direction on a frame above a slide. An oscillating link is perpendicular to the crank shaft and faces a roughly horizontal direction. The oscillating link pivots in a reciprocating manner around an oscillation fulcrum shaft as a center. The oscillation fulcrum shaft is parallel to and at a separate position from a crank shaft. A slider joins rotatably with a crank pin on the crank shaft and is slidable in a linear groove provided in the longitudinal direction of the oscillating link.
A vertical connecting link, has two ends connected in a freely oscillating manner between a lower surface of the oscillating link and the upper surface of the slide. The rotation output of the crank shaft is converted to a reciprocating motion by the oscillating link and the slide operates.
In this related art, the crank shaft is aligned through the front of the slide press, and the oscillating link is perpendicular with this crank shaft. A hole for a crank shaft is perforated on a left-side plate and a right-side plate in the crown. This requirement greatly weakens the frame body and reduces rigidity during operation. This requirement further forces drive mechanisms (motor and fly wheel) to one side of the slide link press, resulting in instability and loss of balance. Compensation for these drawbacks requires a large and expensive frame to minimize vibration and maintain alignment. This cure fails to increase productivity.
Japanese Laid Open Utility Model Publication No. 63-56996, is an example of a rigid press machine requiring a tubular spacer inserted between each column in a front-back and left-right direction. A supporting tie rod passes through the spacer and the columns on either side and binds them together. As a result, the deformation in the columns under load is reduced, and working precision is improved.
However, while the interval between the columns can be maintained, the cross-sectional area of the spacer is small, and the deformation stress of the columns cannot be absorbed. Thus, when an eccentric load is applied on the slide, an edge of the slide contacts the slide guide in a linear manner and xe2x80x98slide gallingxe2x80x99 frequently results and permanently damages the slide guide. When this type of linear contact xe2x80x98slide gallingxe2x80x99 occurs, the slide does not operate smoothly and work precision and productivity greatly suffer.
It is an object of the present invention is to provide a rigid slider link press.
It is another object of the present invention to provide a press with a slide link where the slide decent time is slowed and the ascent time is speeded up.
It is another object of the present invention to provide a press where press torque is increased at bottom dead center.
It is another object of the present invention to provide a press where a center of gravity of a fly wheel is lowered and vibration is reduced.
It is another object of the present invention to provide a press that withstands and absorbs eccentric loads placed on a slide and operates smoothly without undue wear.
It is another object of the present invention to provide a press where a stay and spacer absorb and distribute deformation pressure and prevent frame damage.
It is another object of the present invention to provide a press with horizontal rigidity during press operations.
Briefly stated, the present invention relates to a slider link press which includes an oscillation link operating about a fulcrum shaft and an eccentric crank pin. A connecting link connects the oscillation link to a slide. The oscillating link and fulcrum shaft act to increase press torque and reduce downward press speed while increasing upward press speed. The eccentric crank pin operates the oscillation link, aids in torque increase, and provides reciprocating movement to the slide. A slide includes pivotable slide gibs that engage reciprocal fixed gibs to maintain parallel surface contact and absorb and eliminate eccentric loads on the slide and press. Stays and spacers align sides of the press and eliminates flexing under load while absorbing and distributing eccentric deformation pressure.
According to an embodiment of the present invention, there is provided a slider link press device, comprising: a crank shaft and a fulcrum shaft, first means for linking the crank shaft to the fulcrum shaft, the first means being operable in a first arc about the fulcrum shaft, a crank pin on the crank shaft, the crank pin providing an eccentric displacement to the first means, a slide having a top and a bottom dead center position, second means for linking of the first means to the slide, the first means being effective to receive the eccentric displacement and to operate in the first arc to drive the slide in a cycle, the first means perpendicular to the crank shaft and the fulcrum shaft, the first means permitting an increase in a force applied to the slide at the bottom dead center position and permitting an increase in a slide descent time whereby a precision increases and a slide assent time decreases, guiding means for guiding the slide in a cycle, and the guiding means permitting elimination of eccentric loads upon the slide while the slide operates in the cycle whereby the precision increases.
According to another embodiment of the present invention there is a slider link press device, wherein: the fulcrum shaft includes a fulcrum shaft center, the first link means is horizontal to the fulcrum shaft center at the bottom dead center position, the eccentric displacement is a trajectory circle, an angular velocity of the crank shaft is constant, a first position (O) is a rotation center of the crank shaft, a first tangent point (PT) is defined on the trajectory circle at the top dead center position respective to the fulcrum shaft center, a second tangent point (PR) is defined on the trajectory circle at the bottom dead center position horizontal to the fulcrum shaft center, a first angle (xcex81) is a first link means oscillation angle between the first tangent point (PT), the fulcrum shaft center, and the second tangent point (PR), a second angle (xcex82) is defined between the first tangent point (PT), the first position (O), and the second tangent point (PR), the first angle (xcex81) and the second angle (xcex82) have the following relationship, and
xe2x80x83(xcex82)minimum=180 degreesxe2x88x92(xcex81)xe2x80x83xe2x80x83(I)
(xcex82)maximum=180 degrees+(xcex81)xe2x80x83xe2x80x83(II)
the second link means descends under formula (II) whereby the a torque at the bottom dead center is increased and decent time is increased.
According to another embodiment of the present invention there is provided a slider link press device, wherein: a distance L1 is defined between a maximum eccentricity of said crank pin 11 and said fulcrum shaft center, a distance L2 is defined between the center of said first link means and said fulcrum shaft center, a center of said first link means is a center axis of said slide, a first torque applied to said crank pin is F1, a second torque applied to said slide is F2, said first torque is at a minimum where F1=F2 and said slide is at said top and bottom dead center positions, said slider link press effective to increase during an operating cycle of said slide as said crank pin travels from the top dead center to the bottom dead center, and said second torque is at a maximum at a maximum eccentricity of said crank pin and where F2=F1xc3x97L1/L2 and said first means is effective to increase said second torque.
According to another embodiment of the present invention there is a slider link press device, further comprising: a drive assembly, the drive assembly effective to drive the crank shaft, a speed reducing module and a fly wheel in the drive assembly, a frame assembly supporting the drive assembly and the slide, and the crank shaft above the slide.
According to another embodiment of the present invention there is a slider link press device, wherein: the frame assembly includes a crown assembly, the crown assembly above the slide, the first link means, the crank shaft, and the fulcrum shaft in the crown assembly, and the fly wheel having a center of gravity below the crown, whereby stability is increased and operating vibration is reduced.
According to another embodiment of the present invention there is a slider link press device, wherein: the slide includes a vertical slide center, the slide center being a press center, and the rotation center vertically aligned with the press center.
According to another embodiment of the present invention there is a slider link press device, further comprising: at least first and second columns in the frame, the first and second columns below the crown, at least first and second stays, the first and second stays between the first and second columns at the bottom dead center position, and the first and second stays operably joining the first and second columns whereby the columns are maintained parallel and the frame is rigid and resists high operating pressure and eccentric slide pressure.
According to another embodiment of the present invention there is a slider link press device, further comprising: a plurality of vertical corner surfaces on the slide, a plurality of fixed gibs on the guiding means, the fixed gibs along inner surfaces of the first and second columns, the fixed gibs opposite the slide, the fixed gibs aligned adjacent to the corner surfaces, the corner surfaces being slidably aligned with the fixed gibs, a plurality of slide gibs on the guiding means, the plurality of slide gibs on the corner surfaces, the slide gibs having an engagement surface parallel to the fixed gibs, and means for pivoting the slide gibs relative to the fixed gibs, and the pivoting means effective to maintain the engagement surfaces parallel to the fixed gibs whereby the fixed gibs slidably guide the slide and eliminate eccentric forces on the slide.
According to another embodiment of the present invention there is a slider link press device, further comprising: a plurality of holes in the pivot means, the slide gibs in each the hole, the slide gibs pivotable in each the hole, the holes at a top and bottom side of each the corner surface, the first and second stays are equidistant the slide gibs when the slide is at the bottom dead center position, and the stays, the slide gibs, and the pivot means absorb eccentric forces whereby the first and second columns are maintained in parallel and the slide operates parallel to the fixed gibs.
According to another embodiment of the present invention there is a slider link press device, further comprising: at least one spacer, the spacer between each the stay and each respective the first and second column, the spacer selectable to maintain the first and second columns in parallel, and the spacer being effective as a slip plane whereby the spacer minimizes damage to the first and second columns during tightening the stays.
According to another embodiment of the present invention there is provided a slider link press, having a slide operated by converting a rotational crank shaft output converted to a reciprocating motion by an oscillating link, comprising: an oscillation fulcrum shaft, the oscillation fulcrum shaft parallel to the crank shaft, the oscillating link effective to operably join the oscillation fulcrum shaft and the crank shaft, the oscillating link receiving the output as an eccentric displacement, the oscillating link operation in an arc about the oscillation fulcrum shaft, crank pin on the crank shaft, the crank pin effective to transfer the eccentric displacement to the oscillating link, and the oscillating link effective to transfer the reciprocating motion to the slide and act as a force multiplier whereby the slide operates with increased pressing force, has a lower descent time and a faster ascent time.
According to another embodiment of the present invention there is provided a slider link press, further comprising: a speed reduction module, a fly wheel, the speed reduction module and the fly wheel effective as drive modules for the crank shaft, a frame, the frame including the drive modules and the slide, the fly wheel and the speed reduction modules effective to provide the eccentric displacement to the crank pin whereby the slide operates in a cycle.
According to an embodiment of the present invention there is provided a slider link press device in which a frame includes first and second columns, and a slide operates between the columns, comprising: first and second stays, the first and second stays between the first and second columns, the first and second stays effective to rigidly join the first and second columns, and the first and second stays effect to resist an eccentric force of the crank shaft whereby the first and second columns are maintained in parallel.
According to another embodiment of the present invention there is provided a slider link press device, further comprising: at least one spacer, the spacer between each the first and second column and each respective the first and second stay, and the spacer having a thickness effective to maintain the first and second columns in parallel.
The above, and other objects, features, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.